It has been geenrally recognized by many engine designers that supercharging is one of the more effective ways of improving engine performance, particularly the power output of an engine. However, most prior attempts at using supercharging have utilized a turbine for driving a centrifugal compressor, with the turbine being driven by the engine exhaust gases. While such supercharging systems have produced a noticeable increase in engine output power, they nevertheless have not gained wide acceptance in view of the numereous control problems associated with same, such as the ineffectiveness of the turbine at low engine speeds. Further, under starting conditions, and particularly under cold starting conditions, turbine drives which rely upon exhaust gases are of little, if any, benefit.
In an attempt to improve on the supercharger systems, attempts have been made to utilize different fluids for driving the turbine, specifically freon. However, such a system is disigned to operate as a refrigeration cycle and thus requires that the freon be supplied to a jacket surrounding the combustion chamber for absorbing heat. This system, like the use of exhaust gases, thus relies upon the heat of the engine in order to operate under optimum conditions. This system is also unacceptable under many operating conditions, particularly during starting and warming up of the engine. This system also requires rather elaborate and complex equipment in order for the freon to undergo a proper refrigeration cycle.
Accordingly, it is an object of the present invention to provide an improved turbine-driven supercharger system for use with an internal combustion engine which permits the engine to develop increased power and torque while at the same time providing improved fuel economy. The supercharger system of the present invention also permits quicker cold starting of the engine and faster warmup of the engine since the supercharger system does not rely upon manifold or exhaust heat for the successful operation of same.
It is also an object of the present invention to provide an improved supercharger system, as aforesaid, which permits the gas supplied to the engine to be at a low temperature, which is believed to cause both a significant reduction in exhaust pollutants exhausted and greater volumetric efficiency. Particularly, it is believed that the improved supercharger system of the present invention will reduce all of the major exhaust pollutants, such as carbon monoxide, hydrocarbons and nitrogen oxide. TLhe supercharger system of the present invention, in contrast to conventional engines, will also permit the use of leaner fuel-air mixtures.
A further object of the present invention is to provide an improved supercharger system, as aforesaid, which is combined with the fuel system of the engine to permit fuel to be intermixed with the air in an economical and efficient manner, whereby the conventional complex carburetion system which is normally associated with the engine can be substantially simplified, if not eliminated. Particularly, the system of the present invention permits the elimination of conventional float valves as associated with conventional carburetors, thereby simplifying both the structural and mechanical complexity of the engine.
Still a further object of the present invention is to provide an improved supercharger system, as aforesaid, which utilizes a combustible fuel, and specifically a liquid fuel such as gasoline, for driving the turbine. The fuel for driving the turbine is supplied from a conventional fuel storage tank and is pressurized by means of an intermediate pump. The fuel from the turbine is, in one embodiment of the invention, collected in an intermediate chamber whereby the fuel is drawn through an intermediate tube into a venturi which is located downstream of the supercharger. The intermediate compartment also communicates with the tank for permitting excess fuel to be returned thereto.
Another object of the present invention is to provide a supercharger system which, in accordance with another embodiment, permits the pressurized fuel to be injected into the inflowing air upstream of the turbine, whereby not only is efficient mixing of the air and fuel achieved, but also the overall fuel supply system is substantially simplified.
Other objects and purposes of the present invention will be apparent to persons skilled in this art upon reading the following specification and inspecting the accompanying drawings.